Multiple Cation Substitution and Discussion of Cationic Valence in the Perovskite Oxide

Abstract

Multiple cation substitution in the B site of the perovskite oxide, ABO₃, has been investigated mainly for the 3d transition metal cations under usual preparation conditions, and the cationic valencies have been determined using the electrochemical concept. The maximum number of the kinds of transition metal cations in equivalent amounts were nine for the perovskite oxide prepared in the present study, whose composition is La (TiVCrMnFeCoNiCuZn)₁O₃. It has been concluded from the map of the cationic valencies calculated in the present study that all cations, even Zn and Cu, in the B site exist as M³⁺ in LaMO₃ and that Nb exists as Nb⁵⁺ in La_1-xSr_xMO₃. This has been proved from the measurement of the lattice constants of the perovskites. The maps for the cationic valence have been found to be very useful for the determination of the distribution of the cationic valencies in the B site of the various perovskite oxides.